1. Field
The embodiment relates to a lamp unit and a lighting system for a vehicle.
2. Description of Related Art
In general, a lamp refers to a device for providing or controlling light for the specific purpose. An incandescent bulb, a fluorescent lamp, a neon lamp, etc., may be used as a light source of the lamp, and recently, a light emitting diode (LED) is also being used. The LED is a device which converts an electrical signal into infrared ray or light by using compound semiconductor characteristics. Unlike the fluorescent lamp, the LED does not use harmful substances such as mercury or the like and causes less environmental pollution. The LED has a longer lifespan than those of the incandescent bulb, the fluorescent lamp and the neon lamp. Compared with the incandescent bulb, the fluorescent lamp and the neon lamp, the LED has low power consumption, less glare and excellent visibility due to high color temperature.
A lamp unit may be used in a backlight, a display device, a lighting lamp, an indicating lamp for a vehicle, or a head lamp, etc. In particular, since the lamp unit used in the vehicle is very closely related to safe driving of the vehicle, it is very important to allow a driver of the vehicle adjacent to a traveling vehicle to clearly identify the light emitting states. Therefore, it is necessary that the lamp unit used in the vehicle should obtain not only the light intensity appropriate for safe driving standards but also the aesthetic features of the vehicle's appearance.
Also, the vehicle includes a lighting device which is used to allow a driver to see objects well in a traveling direction when driving and is used to cause drivers of other vehicles and road users to recognize the driving conditions of his/her own vehicle.
Here, the lighting device is a head lamp which is attached to the front of the vehicle and functions to throw light on the road along which the vehicle moves forward. Usually, the head lamp is formed by integrally attaching a low beam for irradiating a short distance and a high beam for irradiating a long distance, so that the low beam or the high beam is lighted according to the driver's choice.
The lighting pattern of the head lamp is required to meet a basic objective to throw light as much as possible in such a manner that the driver is able to obtain the best driving visibility, and is required to also meet an objective to maintain the minimum glare in such a manner that a driver of another vehicle coming from the opposite lane is able to safely drive.
However, such a head lamp for a vehicle provides only fixed directional lighting irrespective of the variously changing ambient conditions, road conditions and the state of the vehicle, and cannot reflect the changes according to the ambient conditions when driving.
Therefore, in a condition where a front visibility is extremely unfavorable, for example, fog, heavy rain or the like, it is hard for the conventional head lamp to obtain sufficient visibility required for safe driving of the driver. Further, in a highway where vehicles travel at a high speed, a larger amount of light capable of traveling a longer distance is necessary due to the speed of the vehicle. However, the conventional head lamp provides a lighting pattern of a general road without satisfying the requirement.
Also, while it is important to obtain ambient visibility and short distance visibility rather than long distance visibility in roads in cities well-equipped with lighting, the conventional head lamp is configured to be suitable for a medium distance and a long distance, so that energy cannot be efficiently utilized.
Additionally, the conventional head lamp is configured to light only the front of the vehicle. Therefore, when the vehicle is tilted by driving on the sloping road of an intersection or a curved road, it is not possible to light in such a manner that the driver can obtain visibility appropriate for this case.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.